int bodyPin = 27;
int BODY_THRES = 3300;

void setup() {
  // put your setup code here, to run once:
  pinMode(bodyPin, INPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  int bodyValue = analogRead(bodyPin);  // digitalRead()
  if (bodyValue < BODY_THRES) {
    Serial.println(1);

    // 触发的内容
    
    delay(100);
  }

}